1. Field of the Invention
The present invention relates to a microstructure diffuser. In particular, the present invention relates to a microstructure diffuser that has a variety of optical structure bodies.
2. Description of Related Art
The technology of diffusers is continuously improved so as to make light beams more uniform. Firstly, a single prism is developed. For example, U.S. Pat. No. 6,606,133 discloses a diffuser that has optical structure on both its light-emitting surface and its light-entering (as shown in FIG. 1). The diffuser 1A has a main body portion 2A. One side surface of the main body portion 2A is the light-entering surface, and another side surface is the light-emitting surface. The light-emitting surface has a prism structure 3A. The light-entering surface has a plurality of convex body structures 4A. However, in a general manufacturing process, the manufacturing process for double-surfaces is difficult, the yield rate is low, and additional problems may occur when the optical film is assembled. U.S. Pat. No. 7,255,456 discloses a diffuser that has two kinds of optical structures respectively on its light-emitting surface and its light-entering surface. These two kinds of optical structures are a prism and a lenticular. This diffuser has the following drawbacks. 1. These two kinds of optical structures merely have a single optical effect. The prism merely has the beam-splitting effect. The lenticular merely has the beam-diffusing effect. Therefore, the uniformity of light beam is not good. 2. The prism has a pointed tip. When the prism is installed with other optical lens, the optical film may be scratched so that the reliability is reduced. 3. When the diffuser is produced, the pointed tip causes the yield rate of the diffuser to reduce, and furthermore it is more difficult to form the diffuser.
In other words, the diffuser of the prior art has problems, such as the uniformity of light beam cannot be enhanced, and the yield rate is low, etc. Thereby, the backlight module may be improved.